Los Angeles County sheriff's officials said they found a possible "honey oil" extraction lab at the location. Investigators were collecting more evidence from the scene on Wednesday.

Evacuated residents were allowed to return to their units a few hours later. Officials said three townhomes were damaged in the fire and one firefighter suffered minor burns to his ears.

The investigation is ongoing. If you have any information about this incident, you're urged to contact the Los Angeles Interagency Metropolitan Police Apprehension Crime Task Force at (323) 869-6874. You can also provide anonymous tips by calling Crime Stoppers at (800) 222-TIPS.